1. Field of the Invention
This invention relates to a touch sensor device and a touch sensor program, especially, those which are useful when applied to an in-vehicle touch sensor device.
2. Description of the Related Art
A touch sensor device finds general purpose use in various industrial fields as an input device which is an interface of various types of instruments. Such a touch sensor device is advantageous in that an operator can operate the instrument merely by touching an arbitrary detection electrode (touch switch) in a touch sensor and, in this respect, can easily perform a predetermined operation. On the other hand, the instrument acts, even when the operator touches the detection electrode unintentionally. Thus, the touch sensor device has the problem that a malfunction is apt to occur. A so-called groping or blind operation, such as for locating the position of the detection electrode, also causes unintended actuation. Such a blind operation becomes a noticeable problem, particularly when operating an in-vehicle instrument while driving a vehicle.
Under these circumstances, conventional technologies have proposed, for example, the following measures: A period during which an output voltage from the touch sensor is equal to or more than a predetermined threshold value—a state assumed to represent a touch on or contact with the detection electrode—is counted with a timer and, when this period is a predetermined time period or longer, an ON determination is made (see Patent Document 1). Alternatively, irregularities are created in the shape of the detection electrode to facilitate the blind operation (see Patent Document 2).
Patent Document 1    JP-A-08-005659
Patent Document 2    JP-A-2005-078104